• Korean Journal of Organic Agriculture
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• v.31 no.3
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• pp.167-189
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• 2023

Korea has become the highest nitrogen balance (228 kg/ha) among 34 OECD member countries, and has the stigma of being a 'Nutrient overload country' as of 2019. Accordingly, research on the derivation and utilization of nutrient balance indicators and the 'regional nutrient management system' are being promoted to improve Korea's nutrient balance. It is necessary to support these policies and studies, form a public consensus on improving the nutrient balance, and evaluate the function of the public benefit. This paper aims to estimate the public benefit value of improving the nutrient balance based on an analysis of consumers' willingness to pay and recognition of Korea's nutrient excess for 600 consumers nationwide. As results, 21.2% of the respondents said they were aware of excessive nutrients in Korea, and 76.7% of the respondents said they were aware of the need for nutrient management. The average amount of intention to pay for the improvement of three pollution (soil, water quality, and air) that can occur due to a nutrient overload was ￦2,321.1 for soil pollution improvement, ￦2,391.2 for water pollution improvement, and ￦2,377.9 for air pollution improvement. The average willingness to pay for the three pollution reduction was ￦6,002.3. These results are expected to be used to form a public consensus on the balance of payments and to establish measures to enhance public interest values in the future.

• Korean Journal of Environmental Biology
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• v.37 no.4
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• pp.554-567
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• 2019

Recently, concerns regarding the environmental impact due to nutrient input in croplands have increased. Therefore, the government is promoting the introduction of a nutrient management system in croplands to solve the problem of excessive nutrient input. This study was carried out to establish nutrient indicators in regional croplands to facilitate the introduction of the national nutrient management system in Korea. The nutrient load and balance indicators for nitrogen and phosphorus were analyzed for nine provinces (Gang-won, Gyeong-gi, Chung-buk, Chung-nam, Jeon-buk, Jeon-nam, Gyeong-buk, Gyeong-nam, and Jeju). In the correlation analysis between the nutrient load and nutrient balance, the correlation coefficient (r) for nitrogen was 0.2504, which was not statistically significant at the 5% significance level. However, the correlation coefficient for phosphorus was 0.7375, which was statistically significant at the 5% significance level. In the nutrient management index, phosphorus showed mutual compatibility between the nutrient load and the nutrient balance indicators, but nitrogen showed no mutual compatibility between the nutrient load and the nutrient balance indicators. Therefore, utilization of the nutrient balance indicator, reflecting the characteristics of the agricultural environment, was more reasonable as a nutrient management index for regional nutrient management.

• Korean Journal of Organic Agriculture
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• v.13 no.4
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• pp.339-355
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• 2005

Nutrient balance is important to develop environmentally friendly agriculture. Phosphorus surplus in nutrient balance was more serious than that of nitrogen. Nitrogen and phosphorus exceeded twice the requirement at 30 cities/counties and 32 among 165, respectively. Given livestock waste and optimal nutrient balance, the proper number of animal feeding was 1.68LU/ha. Considering livestock waste only, the optimal number of livestock feeding was 3,918,000LU (heads) and, including fertilizer that would be 2,288,000LU. It is recommended to introduce the regional control system to regulate nutrient input and output, and the trading system of livestock feeding rights to control that.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.s02
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• pp.1-12
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• 1989

The primary countermeasure for environmental stresses of crops grown in Korea would be to maintain top soil content of available B for upland crops and Si for low land rice in balance with other nutrient elements such as N, P and K, so as to maintain those nutrient balances in plants. Development of standard levels of elements in soils for balances uptake of those elements by plants are needed under the multi nutrient factor balance concept using the soil test results.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.2
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• pp.120-126
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• 2014

An accurate analysis of nutrient balance in different cropping systems is necessary for improving soil fertilities, causing higher crop yields and quality. This study was carried out to investigate the nutrient balance, changes in soil properties, and their effects on crop yield in long-term field cultivation under mono- and rotation-cropping systems (MCS and RCS, respectively). The analytical results of the soil properties showed that the application of mineral fertilizers alone in the MCS leads the reduction of soil CEC, exchangeable Ca, and microbial biomass C and N. Compared with the MCS of soybean, the RCS of soybean and barley significantly improved the soil properties, which increased crop yield. It might be due to the barley residue added to the RCS soil. Mean nutrient balances for 4 years were -55.9 kg N, +34.7 kg $P_2O_5$, and -0.3 kg $K_2O$ $ha^{-1}$ for the MCS and +19.7 kg N, +107.4 kg $P_2O_5$, and -48.6 kg $K_2O$ $ha^{-1}$ for the RCS, respectively. These nutrient imbalances mean that conventional fertilizer recommendations were inadequate for maintaining soil nutrient balance. From these results, we can conclude that the crop rotation may change comprehensive physical, chemical, and biological soil properties. These changes could affect the nutrient balance and then the crop yield.

• Magazine of the Korean Society of Agricultural Engineers
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• v.45 no.7
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• pp.57-69
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• 2003

To evaluate nutrient dynamics with different fertilization in paddy field and develop water quality model, mass balance analysis was performed during growing season of 2001-2002 in field experimental plots irrigated with groundwater. As a result of water balance analysis, most of outflow was surface drainage as about half of total outflow and about 500mm was lost by evapotranspiration. The water budget was well balanced. The runoff from paddy field was influenced by rainfall and forced drain. Especially runoff during early cultural periods more depends on the forced drain. As a result of mass balance analysis, most of nutrient was input by fertilization and lost by plant uptake. Significant amount of nitrogen were supplied by precipitation and input from upper paddy field, comprising 12%∼28% of total inflow. Nutrient loading by surface drainage was occurred showing about 15%∼29% for T-N and 6%∼13% for T-P. The response of rice yield with different fertilization was not significant in this study. Water quality model for paddy field developed using Dirac delta function and continuous source was calibrated and validated to surface water quality monitoring data. It demonstrates good agreement between observed and simulated. The nutrient concentration of surface water at paddy field was significantly influenced by fertilization. During early cultural periods when significant amount of fertilizer was applied, surface drainage from paddy field can cause serious water quality problem. Therefore, reducing surface drainage during fertilization period can reduce nutrient loading from paddy fields. Shallow irrigation, raising the weir height in diked rice fields, and minimizing forced surface drainage are suggested to reduce surface drainage outflow.

• Korean Journal of Environmental Agriculture
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• v.27 no.3
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• pp.267-273
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• 2008

Energy efficiency and nutrient balance are good methods for environmental assessment of the environmentally-friendly agriculture. The objectives of this study were 1) to estimate the energy efficiency and nutrient balance of the organic rice farming, and 2) to suggest a solution to improvement the energy efficiency and nutrient balance. The set of estimation was performed at the organic rice farming area (8.9 ha) in Wanju-gun during the paddy cultivation period from 2006 to 2007. The organic farming complex consists of four weeding methods using 1) duck, 2) apple snail, 3) duck and apple snail and 4) hands and machinery. Results from this estimation should that the organic rice farming area was less efficient than conventional rice farming. The efficiency of organic farming area in 2006 was higher than in 2007. For the calculation of the nutrient balance, the N, P and K contents of input materials (cattle manure, milk vetch, mixed oilcake, rice bran, rice straw and barley straw) and output (farm products) were analysed. Annual environmental loads of N, $P_2O_5$ and $K_2O$ were estimated at 4.4 kg/10a, 13.8 kg/10a and 14.5 kg/10a, respectively. Cattle manure had the largest portion among the inputs items and nutrient concentration of cattle manure was high. Thus energy efficiency and nutrient balance depend on cattle manure input. Therefore it is necessary to control the manure input to improve the efficiency of organic rice farming.

• Journal of The Korean Society of Agricultural Engineers
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• v.55 no.6
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• pp.167-175
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• 2013

The objective of this study was to investigate the nutrient load balance in the reservoir irrigated paddy block during growing seasons. Idong reservoir irrigation paddy block of 10.3 ha in size was selected to collect hydrologic and water quality data. Irrigation, canal flows, and paddy field drainage were measured using a water level gauge, while water samples were collected and analysed for water quality. The water balance analysis showed that 81 % and 75 % of total outflow were through paddy and irrigation canal drainage during 2011 and 2012, respectively. The water quality of paddy field drainage varied greatly depending on rice cultivation stage ranging from 0.05 to 24.55 mg/L and from 0.01 to 0.76 mg/L for T-N and T-P, correspondently. Paddy field drainage loads during May through June account for 64 % and 76 % in 2012 and 2013, while 82 % and 81 % for T-P in 2011 and 2012, respectively. The Pearson correlation analysis showed that rainfall was significantly correlated with nutrient loads during July through August due to runoff, and irrigation was related with nutrient loads of drainage during some period of July through September due to irrigation return flow. This study results showed characteristics of inflow and outflow nutrient loads from plentiful irrigated paddy block.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.3
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• pp.333-339
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• 2010

The objectives of this study were to use the NRC-2001 model and DVE/OEB system to model potential nutrient supply to ruminants and to compare frost damaged (also called "frozen" wheat with normal wheat. Quantitative predictions were made in terms of: i) Truly absorbed rumen synthesized microbial protein in the small intestine; ii) Truly absorbed rumen undegraded feed protein in the small intestine; iii) Endogenous protein in the digestive tract; iv). Total truly absorbed protein in the small intestine; and v). Protein degraded balance. The overall yield losses of the frozen wheat were 24%. Results showed that using the DVE/OEB system to predict the potential nutrient supply, the frozen wheat had similar truly absorbed rumen synthesized microbial protein (65 vs. 66 g/kg DM; p>0.05), tended to have lower truly absorbed rumen undegraded feed protein (39 vs. 53 g/kg DM; p<0.10) and had higher endogenous protein (14 vs. 9 g/kg DM; p<0.05). Total truly absorbed protein in the small intestine was significantly lower (89 vs. 110 g/kg DM, p<0.05) in the frozen wheat. The protein degraded balance was similar and both were negative (-2 vs. -1 g/kg DM). Using the NRC-2001 model to predict the potential nutrient supply, the frozen wheat also had similar truly absorbed rumen synthesized microbial protein (average 56 g/kg DM; p>0.05), tended to have lower truly absorbed rumen undegraded feed protein (35 vs. 48, g/kg DM; p<0.10) and had similar endogenous protein (average 4 g/kg DM; p>0.05). Total truly absorbed protein in the small intestine was significantly lower (95 vs. 108 g/kg DM, p<0.05) in the frozen wheat. The protein degraded balance was not significantly different and both were negative (-16 vs. -19 g/kg DM). In conclusion, both models predict lower protein value and negative protein degraded balance in the frozen wheat. The frost damage to the wheat reduced nutrient content and availability and thus reduced nutrient supply to ruminants by around 12 to 19%.

• Korean Journal of Environmental Agriculture
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• v.42 no.3
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• pp.211-219
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• 2023

Nutrient balance is an environmental indicator for assessing the potential of sustainable agriculture. Improving the use of arable land is crucial for reducing the nutrient balance. This study monitored soil water content, seepage water, crop growth, and nutrient balance in weighing lysimeters during forage barley (Hordeum vulgare L., "Yeongyang") cultivation from October to April. The study was conducted from 2020 to 2022, and the treatments included forage barley cultivation (clay loam, CL-FC; sandy loam, SL-FC) and bare soils. During the regeneration period (March to April), the soil moisture contents of bare and forage barley-cultivated soils were approximately 30-40% and 18.1-21.8%, respectively. The daily evapotranspiration of forage barley was 6.09 mm. The nitrogen balances for SL-FC and CL-FC were -0.43 to -2.93 g m^-2 and -0.79 to 0.75 g m^-2, respectively, which can be attributed to the higher nutrient uptake of forage barley in SL-FC than in CL-FC. Consequently, the forage barley cultivation in SL-FC can potentially reduce nutrient leaching during the spring rainy season. Furthermore, nutrient balance can be reduced by cultivating forage crops during the winter season.